May 2021 Volume 3

FORGING RESEARCH

Additive Manufacturing for Forging Die Fabrication By Prabir K. Chaudhury & Dekland D. H. Barnum

TheAugust 2020 issue of the FIAMagazine [1], publishedby Forging Industry Association (FIA), featured an article on evaluation of forging die fabrication by metal Additive Manufacturing (AM). This article described a project undertaken as part of the Forging Defense Manufacturing Consortium (FDMC) funded by Defense Logistics Agency (DLA). Under this project, the Technology Readiness Level (TRL) andManufacturing Readiness Level (MRL) of metal AM were assessed to evaluate the applicability of this new and emerging technology for fabricating forging dies in support of the DLA mission to serve the warfighters in a timely manner. The technology readiness level, on a scale of 1 to 9, has been assessed based on the guidelines in the Government Accountability Office (GAO) [2], and the manufacturing readiness level, on a scale of 1 to 10 has been assessed following the structured guidelines provided in MRL Deskbook [3]. These assessments show a TRL of 5 and an MRL of 4 for use of metal AM to fabricate forging dies. In addition to the TRL and MRL assessments, this project examined the shortfalls and gaps in manufacturing maturity for implementation of the technology in the acquisition life cycle for forging procurements. A draft Capability Development Document (CDD) has been outlined for further development metal AM for forging die fabrication. The draft CDD focused on the Technology Maturation and Risk Reduction (TMRR) as well as Engineering and Manufacturing Development (EMD). The manufacturing maturity shortfalls and associated risks have been discussed along with manufacturing maturity and risk management. This article provides and update of the accomplishments and future directions established under this project undertaken by FDMC in collaboration with FIA and funded by DLA. Technology andManufacturing Readiness Levels Technology and Manufacturing Readiness was assessed and the reports were published as a deliverable for the project. First, Technology Readiness Assessment (TRA) was conducted based on the most recent (January 2020) TRA guidance published by GAO Best Practices office in GAO-20-48G [2], using bibliometric method to gather and present evidences that are credible, objective, reliable, and useful. Metal AM, in general, and specifically for forging die fabrication have been assessed including the evidences to fulfill the testing requirements of scale, fidelity, and environment. The number of metal AM related scientific peer reviewed journal articles and issued patents as well as substantial number of metal AM parts in service by commercial industry as well as the Department of Defense (DOD) support metal AMTRLs in the 7 to 8 range. However, limited number of metal AM use cases in critical applications suggest the AM technology for forging die fabrication has not reached these levels. Based on the detailed evidences

presented in the TRA Report [4], it has been determined that the TRL for metal AM forging die fabrication is at 5. Current level of manufacturing maturity for forging die fabrication by metal AM has been assessed based on the technological progress supported by the objective evidence of more than 33,000 published articles and more than 600 US patents. In addition, the availability and number of metal AMmachines, facilities, and materials as well as national programs for technology and workforce development have been examined to support the manufacturing readiness assessment. Wohlers Report 2020 [5], the most authoritative global status report on 3D printing and additive manufacturing, shows a strong growth in metal AM materials and machines in the last decade. The total number of metal AMmachines sold per year grew from 125 in 2011 to 2,327 in 2019. Cumulatively more than 10,000 metal AM machines have been installed worldwide for a revenue of more than one billion US Dollar in 2019 alone. The total revenue from metal AM products and services in 2019 is estimated to be close to $4.0 billion, while metal raw materials sales reached $1.12 billion in last nine years. These and other detailed evidence shown in the MRL report [6] indicate that the manufacturing capability to produce forging die using metal AM has been demonstrated in laboratory environment, but lacks production of prototypes in a production environment. Therefore, it is concluded that the forging Based on the evidences shown in the published assessments discussed above, the major manufacturing shortfall is the lack of prototype forging die manufacturing in the production relevant environment. Although there is ample evidence of metal tool [1] and die manufacturing using AM technologies, service conditions of these tools and dies are not as severe as in hot and cold forging operations. The forging industry, especially the die manufacturing supply chain, has limited or no experience in fabricating forging dies using metal AM technologies. One of the major deterrents of using metal AM for forging die manufacturing is the size limitations imposed by current die design practice. The massive size of the forging die sets is not economical for fabrication by metal AM because of the high raw material cost and limitations in metal AM machines. In general, the major shortfalls are: (i) Unavailability of rawmaterials at a reasonable price (ii) Lack of optimized AM processing conditions for consistent and minimum internal defects (iii) Lack of proven forging die performance and durability, and (iv) Inherently large size of forging dies precluding or limiting metal AMmachine utilization. die fabrication by metal AM has reached an MRL of 4. Maturity Shortfalls and Associated Risks

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FIA MAGAZINE | MAY 2021